Clean up SDK Blob storage @ 'latest'

[johnbeisner]

After the renaming effort, many of the assets @ https://dotnetcli.blob.core.windows.net/dotnet/Sdk/release/2.0.0/ are in the older naming convention.

The newly created assets will not overwrite these; remove them.

Examples:
Newer = dotnet-dev-latest-win-x86.exe
Outdated = dotnet-dev-win-x86.latest.exe

[github-actions]

Due to lack of recent activity, this issue has been labeled as 'stale'. It will be closed if no further activity occurs within 30 more days. Any new comment will remove the label.